title: Accumulation, biotransformation, and biochemical responses after exposure to arsenite and arsenate in the estuarine polychaete Laeonereis acuta (Nereididae).
abstract: BACKGROUND
  This study aimed to analyze antioxidant responses and oxidative damage induced by two inorganic forms of arsenic (As; As(III) and As(V)) in an estuarine polychaete species, Laeonereis acuta (Nereididae). The capacity of arsenic biotransformation was also evaluated through the methylation process considering the activity of a key enzyme involved in the metabolization process.
  
  
  METHODS
  Worms were exposed to 50 μg (As(III) or As(V))/l during 2 or 7 days, plus a control group. Endpoints analyzed included concentration of reactive oxygen species (ROS), activities of antioxidant enzymes such as glutathione reductase (GR), total glutathione-S-transferase (GST), and omega isoform (GST Ω), glucose-6-phosphate deshydrogenase (G6PDH), levels of the antioxidant glutathione (GSH), and lipid peroxides concentration (TBARS).
  
  
  CONCLUSIONS
  Results showed: (1) GR inhibition after 2-day exposure to both As forms (p < 0.05); (2) GST Ω inhibition after 7-day exposure to As(III) paralleled by an increase in total GST activity (p < 0.05); (3) augmented G6PDH activity after 7-day exposure to both As forms (p < 0.05); (4) no differences in terms of ROS and TBARS; and (5) inhibition of GST Ω activity in As(III) exposed worms, which was concomitant with a lowering of mono- and dymethylated arsenic species.
  
  
  CONCLUSIONS
  These results confirm the reactivity of some biochemical variables of L. acuta to As and indicates its importance as a sentinel species in estuarine regions with presence of arsenic.
authors.affiliation: Instituto de Ciências Biológicas (ICB), Universidade Federal do Rio Grande-FURG, Cx. P. 474, CEP 96.201-900 Rio Grande, RS, Brazil.
authors.forename: Juliane
authors.initials: J
authors.lastname: Ventura-Lima
authors.forename: Patrícia Baptista
authors.initials: PB
authors.lastname: Ramos
authors.forename: Daniele
authors.initials: D
authors.lastname: Fattorini
authors.forename: Francesco
authors.initials: F
authors.lastname: Regoli
authors.forename: Luis
authors.initials: L
authors.lastname: Ferraz
authors.forename: Leandro Machado
authors.initials: LM
authors.lastname: de Carvalho
authors.forename: José M
authors.initials: JM
authors.lastname: Monserrat
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001149:Arsenates / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D018053:Arsenites / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D001711:Biotransformation; D004784:Environmental Monitoring; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D015227:Lipid Peroxidation; D018384:Oxidative Stress / Q000187:drug effects; D011077:Polychaeta / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D014873:Water Pollutants / Q000378:metabolism* / Q000633:toxicity
chemical_list: D000975:Antioxidants; D001149:Arsenates; D018053:Arsenites; D017382:Reactive Oxygen Species; D014873:Water Pollutants; D005954:Glucosephosphate Dehydrogenase; D005980:Glutathione Reductase; D005982:Glutathione Transferase; D005978:Glutathione; C015001:arsenite; C025657:arsenic acid